Ozone Depletion & Global Warming.

People in the United States now spend over $3 billion annually to correct eye cataracts that can result from exposure to ultraviolet B (UV-B) radiation. The insurance industry is spending tens of billions of dollars to help people whose lives have been disrupted by unusual weather events spawned by global climate change. These facts alone should spur U.S. environmental negotiators to take actions that reduce and eliminate the production, use, and emissions of both ozone depleting and global warming chemicals as soon as technologically feasible.

Industry's long-term reliance on chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), methyl bromide, and other chemicals is resulting in a global atmospheric crisis that cannot be ignored. Normally, the ozone layer blocks nearly all UV-B radiation, which plays a significant role in the formation of skin cancers, eye cataracts, immune system deficiencies, and other health maladies. A 1% loss of stratospheric ozone equals a 2% increase in skin cancers and a nearly 1% increase in eye cataracts worldwide. These are just a few of the reasons why world leaders formulated the 1987 Montreal Protocol on Ozone Depleting Substances, designed to quickly eliminate the use of CFCs and other ozone depleting chemicals.

Ratified by 172 countries and hailed by many experts as the most successful international environmental agreement, the Montreal Protocol has, unfortunately, not succeeded in halting deterioration of the ozone layer. In 1998 and 1999, the Antarctic ozone hole was found to be the largest, deepest, and longest lasting ever. Increased ground-level UV-B radiation has been reported in many parts of the world, including New Zealand and Canada.

Further, in late 1997 and again in late 1999, the European Space Agency reported evidence of an ozone hole over Britain, Belgium, the Netherlands, and Scandinavia. These events were a result of unusually low temperatures in the stratosphere, increasing the rate of ozone depletion caused by ozone consuming chemicals. Consequently, it appears that ozone losses may be more severe than scientists originally anticipated. This news has motivated the European Community to become the most vocal proponent of further actions to protect the ozone layer.

There is also evidence that ozone depletion is masking global warming, because ozone depletion cools the stratosphere even though the earth's surface temperatures are higher than historic averages. Global warming is predicted to cause rising ocean levels, lower plant productivity, and more frequent and dangerous weather patterns. Ozone depletion may also make it harder to combat global warming, because more UV light penetrates the world's oceans and destroys plankton. Plankton plays a pivotal role in the ability of oceans to draw carbon dioxide (the primary global warming chemical) from the atmosphere, thereby making oceans (along with rainforests) important "carbon sinks." Loss of these "sinks" further exacerbates global warming by accelerating the buildup of so-called greenhouse gases in the atmosphere.

Two sets of international agreements seek to address these crises: the Vienna Convention and its 1987 Montreal Protocol for ozone depletion and, for global

warming, the Framework Convention on Climate Change and its 1997 Kyoto Protocol, a highly complex treaty signed by over 175 countries. Although the Montreal Protocol does phase out the worst ozone depleting substances (CFCs, HCFCs, halons, methyl bromide), unfortunately it allows ozone depleting chemicals to be replaced with two greenhouse gases, hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs). Both of these chemicals are among the six global warming gases to be controlled under the Kyoto Protocol.

The Montreal and Kyoto protocols contain mechanisms for reviewing the scientific knowledge, revising control target dates, and banning more chemicals. The Montreal Protocol's Scientific Assessments (1989, 1991, 1994, and 1998) have led, for instance, to the adoption of three amendments to create phase-out schedules for methyl bromide, HCFCs, and other ozone depleting chemicals. The much newer Kyoto Protocol, although not amended to date, has a similar mechanism requiring a scientific review of its provisions.

As we enter the new millennium, the scientific evidence is overwhelming that global warming and ozone depletion are two of the most serious environmental crises ever faced by humankind. Because they are interlinked, there is an urgent need for new strategies that will combat them simultaneously.

Key Points

* The U.S. is spending billions of dollars each year to combat the effects of ozone depletion and global warming on human health and weather patterns.

* Two groundbreaking international treaties, the Montreal and Kyoto protocols, have failed to adequately curb use of the chemicals causing ozone depletion and global warming.

* Ozone depletion and global warming are both man-made and interconnected, and they constitute the most serious environmental crises ever.